Cayuga County Health Department


Hydrilla in Cayuga Lake

Hydrilla, an extremely aggressive aquatic plant, was found in Cayuga Lake adjacent to Wells College in the Village of Aurora in the fall of 2016. If left unchecked, hydrilla will spread rapidly, forming into thick mats of vegetation, making swimming and boating impossible and affecting fish populations.  The impact to the local economy can be significant. 

During the summer of 2017, the U.S. Army Corps of Engineers (USACE), Buffalo District, began a project aimed toward the eradication of hydrilla from this portion of Cayuga Lake.Last year’s treatment was successful in reducing the amount of hydrilla significantly.The USACE is continuing this project in 2018, and is expanding the treatment area compared to last year due to some additional patches found outside the previous treatment area. (See map of 2018 treatment area.) It is anticipated that the treatment during the summer months will continue for a number of years.

National and local experts on Hydrilla agree that the use of herbicides is the best method to achieve eradication of Hydrilla.  The USACE will apply fluridone in a slow release pellet form (trade name Sonar H4C) to treat the Hydrilla in the lake in the primary treatment zone. The primary lake treatment zone consists of an approximately 20-acre area along the shoreline of Cayuga Lake from the outlet of Little Creek to the Wells College Dock. Fluridone will also be applied in 2 smaller areas south of the primary treatment zone, and 1 small area north of the primary treatment zone.

A pelletized copper-based herbicide, tradename Komeen, will be used to spot treat small areas of Hydrilla that are outside of the main treatment area. The spot treatment zones are located north and south of the primary treatment.The north area extends from the Wells College Dock to Sherwood Road. The south area extends from the outlet of Little Creek to Stony Point.Komeen may also be used for spot treatment of limited areas within the main treatment area that do not respond well to the fluridone application.

It is anticipated that the treatment will begin at the end of June through the end of August. The herbicide products will be applied by a New York State licensed professional applicator to the treatment area. Information regarding fluridone can be found here.  Information regarding Komeen can be found here.

At the levels at which the fluridone or Komeen will be applied, there will be no restrictions on drinking, fishing, swimming, boating, or domestic use of treated water. There may be some restrictions on watering certain plants with fluridone treated water. More information on irrigation can be found here (link to fluridone fact sheet).

People with Wilson’s Disease have increased sensitivity to copper and should consult their physician regarding the application of Komeen and any precautions that should be taken. 

The Cayuga County Health Department will conduct water quality monitoring of the public drinking water and the public bathing beach during this treatment period. Sampling results can be found here.

What does Hydrilla look like?


Report suspected hydrilla here

Quick Facts

  • Hydrilla is one of the world’s most invasive plants.
  • Can grow up to a foot a day.
  • Forms thick dense mats that block sunlight and kill native plants.
  • Reduces oxygen in the water and alters fish habitat.
  • Eliminates waterfowl feeding areas and fish spawning sites.
  • Obstructs boating, swimming, and fishing.
  • Lowers the value of waterfront property.
  • Blocks intakes at water treatment, power generation, and industrial facilities.
  • Clogs flood control channels.